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From: <wen.yang99@zte•com.cn>
To: <qiang.zhao@nxp•com>
Cc: wang.yi59@zte•com.cn, zhong.weidong@zte•com.cn,
	linux-kernel@vger•kernel.org, leoyang.li@nxp•com,
	julia.lawall@lip6•fr, linuxppc-dev@lists•ozlabs.org,
	linux-arm-kernel@lists•infradead.org
Subject: Re:RE: [PATCH] soc/fsl/qe: fix err handling of ucc_of_parse_tdm
Date: Tue, 25 Dec 2018 10:53:06 +0800 (CST)	[thread overview]
Message-ID: <201812251053063773660@zte.com.cn> (raw)
In-Reply-To: <VI1PR04MB3247C250649F9CB3490D83A491B40@VI1PR04MB3247.eurprd04.prod.outlook.com>


[-- Attachment #1.1: Type: text/plain, Size: 5421 bytes --]

Hi Qiang,  
Thank you, we'll send a new version to fix this.

Best regards,
  Wen

------------------Original Mail------------------
Sender: QiangZhao <qiang.zhao@nxp•com>
To: wang yi10129963;
CC: zhong weidong10001088;lkml <linux-kernel@vger.kernel.org>julia.lawall@lip6•fr <julia.lawall@lip6•fr>linuxppc-dev <linuxppc-dev@lists•ozlabs.org>wen yang10156314;moderatedlist:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE <linux-arm-kernel@lists•infradead.org>Leo Li <leoyang.li@nxp•com>
Date: 2018/12/25 09:58
Subject: RE: [PATCH] soc/fsl/qe: fix err handling of ucc_of_parse_tdm
Hi Wen,

Will you send another version to resolve the issue described in the comments?

BR
Qiang

> -----Original Message-----
> From: Li Yang <leoyang.li@nxp•com>
> Sent: 2018年12月6日 4:10
> To: wang.yi59@zte•com.cn
> Cc: Qiang Zhao <qiang.zhao@nxp•com>; zhong.weidong@zte•com.cn; lkml
> <linux-kernel@vger•kernel.org>; julia.lawall@lip6•fr; linuxppc-dev
> <linuxppc-dev@lists•ozlabs.org>; wen.yang99@zte•com.cn; moderated
> list:ARM/FREESCALE IMX / MXC ARM ARCHITECTURE
> <linux-arm-kernel@lists•infradead.org>
> Subject: Re: [PATCH] soc/fsl/qe: fix err handling of ucc_of_parse_tdm
>
> On Thu, Nov 22, 2018 at 2:42 PM Yi Wang <wang.yi59@zte•com.cn> wrote:
> >
> > From: Wen Yang <wen.yang99@zte•com.cn>
> >
> > Currently there are 2 problems with the ucc_of_parse_tdm function:
> > 1,a possible null pointer dereference in ucc_of_parse_tdm, detected by
> > the semantic patch deref_null.cocci, with the following warning:
> > drivers/soc/fsl/qe/qe_tdm.c:177:21-24: ERROR: pdev is NULL but
> dereferenced.
> > 2,dev gets modified, so in any case that devm_iounmap() will fail even
> > when the new pdev is valid, because the iomap was done with a different
> pdev.
> > This patch fixes them.
>
> While we are at this, I think this logic need more serious fixing.  I see there is
> no driver bind with the "fsl,t1040-qe-si" or "fsl,t1040-qe-siram" device.  So
> allocating resources using devm_*() with these devices won't provide a
> cleanup path for these resources when the caller fails.  I think we should
> probably allocate resource under device of caller (e.g. ucc-hdlc), so that when
> caller probe fails or is removed it will trigger the cleanup.
>
> >
> > Suggested-by: Christophe LEROY <christophe.leroy@c-s•fr>
> > Signed-off-by: Wen Yang <wen.yang99@zte•com.cn>
> > CC: Julia Lawall <julia.lawall@lip6•fr>
> > CC: Zhao Qiang <qiang.zhao@nxp•com>
> > ---
> >  drivers/soc/fsl/qe/qe_tdm.c | 20 ++++++++++----------
> >  1 file changed, 10 insertions(+), 10 deletions(-)
> >
> > diff --git a/drivers/soc/fsl/qe/qe_tdm.c b/drivers/soc/fsl/qe/qe_tdm.c
> > index f78c346..9a29f0b 100644
> > --- a/drivers/soc/fsl/qe/qe_tdm.c
> > +++ b/drivers/soc/fsl/qe/qe_tdm.c
> > @@ -47,7 +47,7 @@ int ucc_of_parse_tdm(struct device_node *np, struct
> ucc_tdm *utdm,
> >         struct resource *res;
> >         struct device_node *np2;
> >         static int siram_init_flag;
> > -       struct platform_device *pdev;
> > +       struct platform_device *pdev_si, *pdev_siram;
> >
> >         sprop = of_get_property(np, "fsl,rx-sync-clock", NULL);
> >         if (sprop) {
> > @@ -129,16 +129,16 @@ int ucc_of_parse_tdm(struct device_node *np,
> struct ucc_tdm *utdm,
> >         if (!np2)
> >                 return -EINVAL;
> >
> > -       pdev = of_find_device_by_node(np2);
> > -       if (!pdev) {
> > +       pdev_si = of_find_device_by_node(np2);
> > +       if (!pdev_si) {
> >                 pr_err("%pOFn: failed to lookup pdev\n", np2);
> >                 of_node_put(np2);
> >                 return -EINVAL;
> >         }
> >
> >         of_node_put(np2);
> > -       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > -       utdm->si_regs = devm_ioremap_resource(&pdev->dev, res);
> > +       res = platform_get_resource(pdev_si, IORESOURCE_MEM, 0);
> > +       utdm->si_regs = devm_ioremap_resource(&pdev_si->dev, res);
> >         if (IS_ERR(utdm->si_regs)) {
> >                 ret = PTR_ERR(utdm->si_regs);
> >                 goto err_miss_siram_property; @@ -150,8 +150,8 @@
> int
> > ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm,
> >                 goto err_miss_siram_property;
> >         }
> >
> > -       pdev = of_find_device_by_node(np2);
> > -       if (!pdev) {
> > +       pdev_siram = of_find_device_by_node(np2);
> > +       if (!pdev_siram) {
> >                 ret = -EINVAL;
> >                 pr_err("%pOFn: failed to lookup pdev\n", np2);
> >                 of_node_put(np2);
> > @@ -159,8 +159,8 @@ int ucc_of_parse_tdm(struct device_node *np, struct
> ucc_tdm *utdm,
> >         }
> >
> >         of_node_put(np2);
> > -       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > -       utdm->siram = devm_ioremap_resource(&pdev->dev, res);
> > +       res = platform_get_resource(pdev_siram, IORESOURCE_MEM, 0);
> > +       utdm->siram = devm_ioremap_resource(&pdev_siram->dev, res);
> >         if (IS_ERR(utdm->siram)) {
> >                 ret = PTR_ERR(utdm->siram);
> >                 goto err_miss_siram_property; @@ -174,7 +174,7 @@
> int
> > ucc_of_parse_tdm(struct device_node *np, struct ucc_tdm *utdm,
> >         return ret;
> >
> >  err_miss_siram_property:
> > -       devm_iounmap(&pdev->dev, utdm->si_regs);
> > +       devm_iounmap(&pdev_si->dev, utdm->si_regs);
> >         return ret;
> >  }
> >  EXPORT_SYMBOL(ucc_of_parse_tdm);
> > --
> > 2.9.5
> >

      reply	other threads:[~2018-12-25  2:55 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-11-22  6:49 [PATCH] soc/fsl/qe: fix err handling of ucc_of_parse_tdm Yi Wang
2018-12-05 20:09 ` Li Yang
2018-12-25  1:58   ` Qiang Zhao
2018-12-25  2:53     ` wen.yang99 [this message]

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